An engine valve control mechanism for varying the amount of opening and/or timing of a cylinder valve in a valve gear train of a multi-cylinder, internal combustion engine having an overhead camshaft which actuates the valve via a rocker arm pivotally bridged between the valve stem and a hydraulic lash adjuster. In one engine embodiment of the invention, the valve gear train portion for each intake valve is provided with a valve control mechanism of the invention by providing a camshaft having a high lift lobe and two low lift lobes for actuating the valve and by providing a valve rocker arm including a rigid link defining a first cam follower for following the low lift lobes and a second cam follower pivotally connected to the rigid link for following the high lift lobe. A latch, carried by the rigid link, is operative in a first position to prevent pivotal movement of the second follower relative to the rigid link, whereby the valve is actuated by the high lift lobe, and operative in a second position to allow such pivotal movement, whereby the valve is actuated by the low lift lobes. The latch is operated by a solenoid supported by the lash adjuster. In a second embodiment of the invention, the low lift lobes are removed, whereby the valves are disabled when the latch is in the second position.